Machine Learning BBPct [BackQuant]Machine Learning BBPct
What this is (in one line)
A Bollinger Band %B oscillator enhanced with a simplified K-Nearest Neighbors (KNN) pattern matcher. The model compares today’s context (volatility, momentum, volume, and position inside the bands) to similar situations in recent history and blends that historical consensus back into the raw %B to reduce noise and improve context awareness. It is informational and diagnostic—designed to describe market state, not to sell a trading system.
Background: %B in plain terms
Bollinger %B measures where price sits inside its dynamic envelope: 0 at the lower band, 1 at the upper band, ~ 0.5 near the basis (the moving average). Readings toward 1 indicate pressure near the envelope’s upper edge (often strength or stretch), while readings toward 0 indicate pressure near the lower edge (often weakness or stretch). Because bands adapt to volatility, %B is naturally comparable across regimes.
Why add (simplified) KNN?
Classic %B is reactive and can be whippy in fast regimes. The simplified KNN layer builds a “nearest-neighbor memory” of recent market states and asks: “When the market looked like this before, where did %B tend to be next bar?” It then blends that estimate with the current %B. Key ideas:
• Feature vector . Each bar is summarized by up to five normalized features:
– %B itself (normalized)
– Band width (volatility proxy)
– Price momentum (ROC)
– Volume momentum (ROC of volume)
– Price position within the bands
• Distance metric . Euclidean distance ranks the most similar recent bars.
• Prediction . Average the neighbors’ prior %B (lagged to avoid lookahead), inverse-weighted by distance.
• Blend . Linearly combine raw %B and KNN-predicted %B with a configurable weight; optional filtering then adapts to confidence.
This remains “simplified” KNN: no training/validation split, no KD-trees, no scaling beyond windowed min-max, and no probabilistic calibration.
How the script is organized (by input groups)
1) BBPct Settings
• Price Source – Which price to evaluate (%B is computed from this).
• Calculation Period – Lookback for SMA basis and standard deviation.
• Multiplier – Standard deviation width (e.g., 2.0).
• Apply Smoothing / Type / Length – Optional smoothing of the %B stream before ML (EMA, RMA, DEMA, TEMA, LINREG, HMA, etc.). Turning this off gives you the raw %B.
2) Thresholds
• Overbought/Oversold – Default 0.8 / 0.2 (inside ).
• Extreme OB/OS – Stricter zones (e.g., 0.95 / 0.05) to flag stretch conditions.
3) KNN Machine Learning
• Enable KNN – Switch between pure %B and hybrid.
• K (neighbors) – How many historical analogs to blend (default 8).
• Historical Period – Size of the search window for neighbors.
• ML Weight – Blend between raw %B and KNN estimate.
• Number of Features – Use 2–5 features; higher counts add context but raise the risk of overfitting in short windows.
4) Filtering
• Method – None, Adaptive, Kalman-style (first-order),
or Hull smoothing.
• Strength – How aggressively to smooth. “Adaptive” uses model confidence to modulate its alpha: higher confidence → stronger reliance on the ML estimate.
5) Performance Tracking
• Win-rate Period – Simple running score of past signal outcomes based on target/stop/time-out logic (informational, not a robust backtest).
• Early Entry Lookback – Horizon for forecasting a potential threshold cross.
• Profit Target / Stop Loss – Used only by the internal win-rate heuristic.
6) Self-Optimization
• Enable Self-Optimization – Lightweight, rolling comparison of a few canned settings (K = 8/14/21 via simple rules on %B extremes).
• Optimization Window & Stability Threshold – Governs how quickly preferred K changes and how sensitive the overfitting alarm is.
• Adaptive Thresholds – Adjust the OB/OS lines with volatility regime (ATR ratio), widening in calm markets and tightening in turbulent ones (bounded 0.7–0.9 and 0.1–0.3).
7) UI Settings
• Show Table / Zones / ML Prediction / Early Signals – Toggle informational overlays.
• Signal Line Width, Candle Painting, Colors – Visual preferences.
Step-by-step logic
A) Compute %B
Basis = SMA(source, len); dev = stdev(source, len) × multiplier; Upper/Lower = Basis ± dev.
%B = (price − Lower) / (Upper − Lower). Optional smoothing yields standardBB .
B) Build the feature vector
All features are min-max normalized over the KNN window so distances are in comparable units. Features include normalized %B, normalized band width, normalized price ROC, normalized volume ROC, and normalized position within bands. You can limit to the first N features (2–5).
C) Find nearest neighbors
For each bar inside the lookback window, compute the Euclidean distance between current features and that bar’s features. Sort by distance, keep the top K .
D) Predict and blend
Use inverse-distance weights (with a strong cap for near-zero distances) to average neighbors’ prior %B (lagged by one bar). This becomes the KNN estimate. Blend it with raw %B via the ML weight. A variance of neighbor %B around the prediction becomes an uncertainty proxy ; combined with a stability score (how long parameters remain unchanged), it forms mlConfidence ∈ . The Adaptive filter optionally transforms that confidence into a smoothing coefficient.
E) Adaptive thresholds
Volatility regime (ATR(14) divided by its 50-bar SMA) nudges OB/OS thresholds wider or narrower within fixed bounds. The aim: comparable extremeness across regimes.
F) Early entry heuristic
A tiny two-step slope/acceleration probe extrapolates finalBB forward a few bars. If it is on track to cross OB/OS soon (and slope/acceleration agree), it flags an EARLY_BUY/SELL candidate with an internal confidence score. This is explicitly a heuristic—use as an attention cue, not a signal by itself.
G) Informational win-rate
The script keeps a rolling array of trade outcomes derived from signal transitions + rudimentary exits (target/stop/time). The percentage shown is a rough diagnostic , not a validated backtest.
Outputs and visual language
• ML Bollinger %B (finalBB) – The main line after KNN blending and optional filtering.
• Gradient fill – Greenish tones above 0.5, reddish below, with intensity following distance from the midline.
• Adaptive zones – Overbought/oversold and extreme bands; shaded backgrounds appear at extremes.
• ML Prediction (dots) – The KNN estimate plotted as faint circles; becomes bright white when confidence > 0.7.
• Early arrows – Optional small triangles for approaching OB/OS.
• Candle painting – Light green above the midline, light red below (optional).
• Info panel – Current value, signal classification, ML confidence, optimized K, stability, volatility regime, adaptive thresholds, overfitting flag, early-entry status, and total signals processed.
Signal classification (informational)
The indicator does not fire trade commands; it labels state:
• STRONG_BUY / STRONG_SELL – finalBB beyond extreme OS/OB thresholds.
• BUY / SELL – finalBB beyond adaptive OS/OB.
• EARLY_BUY / EARLY_SELL – forecast suggests a near-term cross with decent internal confidence.
• NEUTRAL – between adaptive bands.
Alerts (what you can automate)
• Entering adaptive OB/OS and extreme OB/OS.
• Midline cross (0.5).
• Overfitting detected (frequent parameter flipping).
• Early signals when early confidence > 0.7.
These are purely descriptive triggers around the indicator’s state.
Practical interpretation
• Mean-reversion context – In range markets, adaptive OS/OB with ML smoothing can reduce whipsaws relative to raw %B.
• Trend context – In persistent trends, the KNN blend can keep finalBB nearer the mid/upper region during healthy pullbacks if history supports similar contexts.
• Regime awareness – Watch the volatility regime and adaptive thresholds. If thresholds compress (high vol), “OB/OS” comes sooner; if thresholds widen (calm), it takes more stretch to flag.
• Confidence as a weight – High mlConfidence implies neighbors agree; you may rely more on the ML curve. Low confidence argues for de-emphasizing ML and leaning on raw %B or other tools.
• Stability score – Rising stability indicates consistent parameter selection and fewer flips; dropping stability hints at a shifting backdrop.
Methodological notes
• Normalization uses rolling min-max over the KNN window. This is simple and scale-agnostic but sensitive to outliers; the distance metric will reflect that.
• Distance is unweighted Euclidean. If you raise featureCount, you increase dimensionality; consider keeping K larger and lookback ample to avoid sparse-neighbor artifacts.
• Lag handling intentionally uses neighbors’ previous %B for prediction to avoid lookahead bias.
• Self-optimization is deliberately modest: it only compares a few canned K/threshold choices using simple “did an extreme anticipate movement?” scoring, then enforces a stability regime and an overfitting guard. It is not a grid search or GA.
• Kalman option is a first-order recursive filter (fixed gain), not a full state-space estimator.
• Hull option derives a dynamic length from 1/strength; it is a convenience smoothing alternative.
Limitations and cautions
• Non-stationarity – Nearest neighbors from the recent window may not represent the future under structural breaks (policy shifts, liquidity shocks).
• Curse of dimensionality – Adding features without sufficient lookback can make genuine neighbors rare.
• Overfitting risk – The script includes a crude overfitting detector (frequent parameter flips) and will fall back to defaults when triggered, but this is only a guardrail.
• Win-rate display – The internal score is illustrative; it does not constitute a tradable backtest.
• Latency vs. smoothness – Smoothing and ML blending reduce noise but add lag; tune to your timeframe and objectives.
Tuning guide
• Short-term scalping – Lower len (10–14), slightly lower multiplier (1.8–2.0), small K (5–8), featureCount 3–4, Adaptive filter ON, moderate strength.
• Swing trading – len (20–30), multiplier ~2.0, K (8–14), featureCount 4–5, Adaptive thresholds ON, filter modest.
• Strong trends – Consider higher adaptive_upper/lower bounds (or let volatility regime do it), keep ML weight moderate so raw %B still reflects surges.
• Chop – Higher ML weight and stronger Adaptive filtering; accept lag in exchange for fewer false extremes.
How to use it responsibly
Treat this as a state descriptor and context filter. Pair it with your execution signals (structure breaks, volume footprints, higher-timeframe bias) and risk management. If mlConfidence is low or stability is falling, lean less on the ML line and more on raw %B or external confirmation.
Summary
Machine Learning BBPct augments a familiar oscillator with a transparent, simplified KNN memory of recent conditions. By blending neighbors’ behavior into %B and adapting thresholds to volatility regime—while exposing confidence, stability, and a plain early-entry heuristic—it provides an informational, probability-minded view of stretch and reversion that you can interpret alongside your own process.
Bbpct
Bollinger Bands Percentile + Stdev Channels (BBPct) [AlgoAlpha]Description:
The "Bollinger Bands Percentile (BBPct) + STD Channels" mean reversion indicator, developed by AlgoApha, is a technical analysis tool designed to analyze price positions using Bollinger Bands and Standard Deviation Channels (STDC). The combination of these two indicators reinforces a stronger reversal signal. BBPct calculates the percentile rank of the price's standard deviation relative to a specified lookback period. Standard deviation channels operate by utilizing a moving average as the central line, with upper and lower lines equidistant from the average based on the market's volatility, helping to identify potential price boundaries and deviations.
How it Works:
The BBPct indicator utilizes Bollinger Bands, which consist of a moving average (basis) and upper and lower bands based on a specified standard deviation multiplier. By default, it uses a 20-period moving average and a standard deviation multiplier of 2. The upper band is calculated by adding the basis to the standard deviation multiplied by the multiplier, while the lower band is calculated by subtracting the same value. The BBPct indicator calculates the position of the current price between the lower and upper Bollinger Bands as a percentile value. It determines this position by comparing the price's distance from the lower band to the overall range between the upper and lower bands. A value of 0 indicates that the price is at the lower band, while a value of 100 indicates that the price is at the upper band. The indicator also includes an optional Bollinger Band standard deviation percentage (%Stdev) histogram, representing the deviation of the current price from the moving average as a percentage of the price itself.
Standard deviation channels, also known as volatility channels, aid in identifying potential buying and selling opportunities while minimizing unfavorable trades. These channels are constructed by two lines that run parallel to a moving average. The separation between these lines is determined by the market's volatility, represented by standard deviation. By designating upper and lower channel lines, the channels demarcate the borders between typical and atypical price movements. Consequently, when the market's price falls below the lower channel line, it suggests undervaluation, whereas prices surpassing the upper channel line indicate overvaluation.
Signals
The chart displays potential reversal points through the use of red and green arrows. A red arrow indicates a potential bearish retracement, signaling a possible downward movement, while a green arrow represents a potential pullback to the positive, suggesting a potential upward movement. These signals are generated only when both the BBPct (Bollinger Bands Percentage) and the STDC (Standard Deviation Channel) indicators align with bullish or bearish conditions. Consequently, traders might consider opening long positions when the green arrow appears and short positions when the red arrow is plotted.
Usage:
This indicator can be utilized by traders and investors to effectively identify pullbacks, reversals, and mean regression, thereby enhancing their trading opportunities. Notably, extreme values of the BBPct, such as below -5 or above 105, indicate oversold or overbought conditions, respectively. Moreover, the presence of extreme STDC zones occurs when prices fall below the lower channel line or cross above the upper channel line. Traders can leverage this information as a mean reversion tool by identifying instances of peak overbought and oversold values. These distinctive characteristics facilitate the identification of potential entry and exit points, thus augmenting trading decisions and enhancing market analysis.
The indicator's parameters, such as the length of the moving average, the data source, and the standard deviation multiplier, can be customized to align with individual trading strategies and preferences.
Originality:
The BBPct + STDC indicator, developed by AlgoAlpha, is an original implementation that combines the calculation of Bollinger Bands, percentile ranking, the %Stdev histogram and the STDC. While it shares some similarities with the Bollinger Bands %B indicator, the BBPct indicator introduces additional elements and customization options tailored to AlgoAlpha's methodology. The script is released under the Mozilla Public License 2.0, granting users the freedom to utilize and modify it while adhering to the license terms.
Bollinger Band Percentile SuiteThe Bollinger Band Percentile Suite (𝐵𝐵𝒫𝒸𝓉 𝒮𝓊𝒾𝓉𝑒) is a comprehensive and customizable toolkit built upon the foundation of the %B indicator. The methodology behind this toolkit remains consistent with the original %B indicator, while introducing a host of powerful features to enhance its functionality and adaptability.
Key Features and Customization:
The 𝐵𝐵𝒫𝒸𝓉 offers a wide array of customizable options to suit your trading preferences and strategies. It includes a variety of 14 moving average types that can be chosen as the basis for the Bollinger Band calculation. Additionally, traders have the flexibility to set their upper and lower boundaries for mean reversion detection, allowing for analysis tailored to the user's preference.
Deviation Calculation:
The toolkit provides an option to choose between standard and weighted deviation calculation methods. This added customization ensures that the indicator's behavior aligns with your unique trading style and preferences.
Signals and Reversals:
The 𝐵𝐵𝒫𝒸𝓉 excels in identifying potential overbought and oversold market conditions. It highlights these levels on the chart and marks potential reversal signals with small circles positioned either at the top or bottom of the indicator pane, providing traders with actionable insights.
Trend and Color Coding:
Incorporating a color-coded approach, the BBpct Suite enhances your understanding of market dynamics. It offers bar coloring options based on trend, allowing traders to identify bullish or bearish market conditions as the percentile goes above or below the midline.
Extremities and Reversions:
Recognizing extreme market conditions is crucial for traders. The 𝐵𝐵𝒫𝒸𝓉 includes color-coded indicators for extremities, indicating when the percentile ventures above or below the predefined thresholds. Moreover, it promptly identifies reversions by marking the moment the percentile crosses under the upper threshold (overbought) or over the lower threshold (oversold).
The Bollinger Band Percentile Suite equips traders with a versatile toolkit to gain valuable insights into market overbought and oversold conditions, and potential reversal signals. Its extensive customization options and array of features empower traders to make well-informed decisions based on their unique trading strategies and risk tolerance.
Please note that while the BBpct Suite provides robust analysis, it is advisable to combine its insights with other technical indicators and tools for a comprehensive trading approach.
Example Chart:
Reversion Zone IndexThe Reversion Zone Index (RZI) is an indicator that combines the Commodity Channel Index (CCI), Choppiness Index (CI), and Bollinger Bands Percentage (BBPct) to identify mean reversion signals in the market. It is plotted as an Exponential Moving Average (EMA) smoothed oscillator with overbought and oversold zones, and mean reversion signals are represented by red and green arrows.
The three indicators are combined to benefit from their complementary aspects and create a more comprehensive view of mean reversion conditions. Here's a brief overview of each indicator's benefits:
1. Commodity Channel Index (CCI): CCI measures the current price level relative to its average over a specified period. It helps identify overbought and oversold conditions, as well as potential trend retracements. By incorporating CCI, the RZI gains insights into momentum and potential turning points.
2. Choppiness Index (CI): CI quantifies the market's choppiness or trendiness by analyzing the range between the highest high and lowest low over a specific period. It indicates whether the market is in a trending or ranging phase. CI provides valuable information about the market state, which can be useful in mean reversion analysis.
3. Bollinger Bands Percentage (BBPct): BBPct measures the current price's position relative to the Bollinger Bands. It calculates the percentage difference between the current price and the bands, identifying potential overbought or oversold conditions. BBPct helps gauge the market's deviation from its typical behavior and highlights potential reversal opportunities.
The RZI combines the three indicators by taking an average of their values and applying further calculations. It smooths the combined oscillator using an EMA to reduce noise and enhance the visibility of the trends. Smoothing with EMA provides a more responsive representation of the overall trend and helps filter out short-term fluctuations.
The overbought and oversold zones are marked on the chart as reference levels. When the combined oscillator is above the overbought zone or below the oversold zone, it suggests a potential mean reversion signal. Red and green arrows are displayed to visually indicate these mean retracement signals.
The RZI is a valuable tool for identifying mean reversion opportunities in the market. It incorporates multiple indicators, each providing unique insights into different aspects of mean reversion, such as momentum, volatility, and price positioning. Traders can use this indicator to spot potential turning points and time their trades accordingly.
